Sources of N and K affecting wheat diseases

Communications in Plant Sciences, vol 9, p. 100-107, 2019 (2019017)
DOI: http://dx.doi.org/10.26814/cps2019017

Nitrogen and potassium sources of fertilizers may affect wheat blast and Fusarium head blight under favorable weather conditions

Sérgio Ricardo Silva*, Adriano Augusto de Paiva Custódio, José Salvador Simonetto Foloni and Manoel Carlos Bassoi
*Correspondence to: sergio.ricardo@embrapa.br

Abstract: Wheat blast (WB) and Fusarium head blight (FHB) are important wheat spike diseases in South America. There is evidence that the severity of these diseases is influenced by soil fertilization. The effects of nitrogen (N) and potassium (K) sources of fertilizers and phenological stages for topdressing fertilization on these spike diseases were evaluated during the 2015 and 2016 winter seasons in an endemic area for these diseases in Brazil. Two distinct field experiments were carried out, one focusing on N sources and the other on K sources. The experimental design was a complete randomized blocks, with four replicates, and the treatments were disposed in a 2 x 3 x 3 factorial: two wheat genotypes (BRS Gaivota and BRS Gralha-Azul), three sources of N or K, and three phenological stages for fertilization. The WB and FHB severities in BRS Gralha-Azul were higher than that in BRS Gaivota. FHB severity was lower when N was applied in the booting stage than in flowering. The sources of K influenced FHB severity, which was higher when K chloride was applied, compared with K nitrate. The weather condition was the determining factor in the wheat expression to WB and FHB diseases, followed by genotype resistance.

Highlighted Conclusions
1. Nitrogen and K sources of fertilizers and the phenological stages for N and K fertilizations do not play a significant role on wheat expression to WB and FHB.
2. Weather condition is the determining factor in the wheat expression to WB and FHB, followed by genotype resistance.

Keywords: Triticum aestivum, Magnaporthe oryzae Triticum pathotype, Fusarium graminearum, Wheat spike diseases, Nutrient-plant disease interaction. (more…)

Soybean responses to soil micronutrient fertilization

Communications in Plant Sciences, vol 9, p. 93-99, 2019 (2019016)
DOI: http://dx.doi.org/10.26814/cps2019016

Nutritional and morphophysiological responses of soybean to micronutrient fertilization in soil

Rubens Ribeiro da Silva*, Larissa Urzêdo Rodrigues, Rodrigo Ribeiro Fidélis, Álvaro José Gomes de Faria and Vitor L. Nascimento
*Correspondence to: rrs2002@uft.edu.br

Abstract: Micronutrient fertilization is essential to meet the nutritional deficiency of plants, providing the full development of crops. The aim of this work was to evaluate the effects of fertilization with micronutrients applied in the soil on the nutrition and morphology of soybean plants. The experimental design was completely randomized, with four replications. The treatments consisted of fertilization with micronutrients applied to soil to reach three levels of availability of B: low (<0.15 mg dm-3 – control), good (0.61 mg dm-3) and high (> 0.90 mg dm-3). For this, the following values were applied: 0.00 (control), 56.67 and 211.11 kg ha-1 of the fertilizer containing 1.8% B, 0.85% Cu, 2% Mn and 9% Zn. Fertilization with the good and high treatments did not affect the uptake of B, but increased the Cu and Mn content, and reduced the Zn content in the plants. Higher plants with greater leaf expansion were observed in the high treatment, however, this did not influence the soybean grain yield. In the control, the physiological activity revealed smaller A, whereas gs and Ci were more effective; reverse effect was observed with high treatment. Fertilization with micronutrients in the soil affects the nutritional status and the photosynthetic activity of the plants due to the imbalance in the concentrations of B, Cu, Mn and Zn supplied with the fertilizer, reflecting in the absence of gains in the production of soybean grains.

Highlighted Conclusions
1. Fertilization with micronutrients in the soil using as criterion the reach of three levels of availability of B does not increase the production of biomass and grains, despite ensuring foliar contents of B (Ȳ= 40.40) and Cu (Ȳ= 23.06) suitable for soybean cultivation in the Cerrado.
2. The inequity in the concentrations of B, Cu, Mn and Zn supplied with fertilizer affects the physiological performance of soybean plants.

Keywords: Glycine max L., Low solubility fertilizer, Plant nutrition, Photosynthesis. (more…)

Association of fungicides on Puccinia triticina and wheat

Communications in Plant Sciences, vol 9, p. 88-92, 2019 (2019015)
DOI: http://dx.doi.org/10.26814/cps2019015

Association of multisite and site-specific fungicides in the control of Puccinia triticina and its effects on wheat yield

Deivid Sacon, Aline Netto, Alessandra Gallina, Eduardo Silvestrini Tonello and Paola Mendes Milanesi
*Correspondence to: deividsacon@hotmail.com

Abstract: The wheat (Triticum aestivum L.) crop has great importance in the national context, the diseases are one of the main factors of losses, which emphasizes the importance of the pest system Triticum aestivum L. x Puccinia triticina Eriks. The aim of this study was to evaluate the efficiency of the combination of site-specific and multisite fungicides in the control of wheat leaf rust and its effects on crop yield. The evaluated treatments were: Control (absence of fungicide application); T + P (trifloxystrobin + prothioconazole); P + F (pyraclostrobin + fluxapyroxad); T + P + Mb (trifloxystrobin + prothioconazole + mancozeb); P + F + Mb (pyraclostrobin + fluxapyroxad + mancozeb) and Mb (mancozeb). Greater control of the disease was observed with the association of fungicides, there is a correlation between control and crop productivity, especially in harvest with greater severity of the disease.

Highlighted Conclusions
1. At low severity the wheat leaf rust does not present damage on crop productivity.
2. The association of multisite and site-specific fungicides increases the disease control effect.
3. The application fungicide program with the association of different a.i. maintains the crop yield potential.
4. The disease control has a positive effect on the yield components, on the other hand, the AUDPC presents a negative correlation.

Keywords: Leaf rust, Mancozeb, Chemical control. (more…)

Crop and soil management on soil resistance

Communications in Plant Sciences, vol 9, p. 84-87, 2019 (2019014)
DOI: http://dx.doi.org/10.26814/cps2019014

Crop rotation and soil scarification: impacts in the soil penetration resistance

Alexandra da Silva Martinez*, Edleusa Pereira Seidel, Renan Pan, Tauane Santos Brito, Wesler Meiners Caciano and Leticia Gabriela Ertel
*Correspondence to: alexandra26martinez@gmail.com

Abstract: TThe objective of the present study was to evaluate the soil penetration resistance of an Oxisoil under a crop rotation system with mechanical and/or biological scarification. A randomized block design, with four replicates, was used, with the following treatments: sowing of a mix of forage radish and black oat followed by mechanical scarification right after it was sowed; sowing of a mix of forage radish and black oat without mechanical scarification; sowing of maize second crop and scarification right after its harvest; sowing of maize second crop with sowing of buckwheat right after its harvest; sowing of maize second crop (control). All treatments were followed by the sowing of soybean in October 2018. It was evaluated, in five spots per plot, the soil penetration resistance in the 0-40 cm depth, with the digital penetrometer Falker® PLG 1020. All treatments presented a reduction in the soil penetration resistance, with values inferior to 2.00 MPa, which is the critical limit for most crops. In all treatments tested, the penetration resistance tended to equality in the depth of 40 cm.

Highlighted Conclusion
The mechanical scarification can be used to increase the soil water infiltration since results in improvements in the soil physical properties if performed right after the mix of forage radish and black oat was sowed or right after the maize harvest.

Keywords: Winter cover crops, Soil decompression, Soil and water management, Soil and water conservation. (more…)

Black pepper production by small farmers

Communications in Plant Sciences, vol 9, p. 81-83, 2019 (2019013)
DOI: http://dx.doi.org/10.26814/cps2019013

Growing of black pepper by small farmers in the city of Capitão Poço, PA, Brazil

Letícia do Socorro Cunha*, Luane Laíse Oliveira Ribeiro, Felipe Cunha do Rego, Francisco Lailson da Silva de Oliveira, Alysson Oliveira de Carvalho, Luã Souza de Oliveira, Marcos Vinicius Reis de Oliveira Junior, Jéssica da Silva Schmidt, Fernanda Ludmyla Barbosa de Souza, Emerson Fey, Wanderson Cunha Pereira and Francisca das Chagas Bezerra de Araújo
*Correspondence to: leticiacunhaufra2013@hotmail

Abstract: The objective of this work was to conduct a study on the cultivation of black pepper by small farmers in the city of Capitão Poço / PA. The research was developed based on the application of semi-structured questionnaires, in order to identify the form of cultivation of black pepper in the municipality carried out by family farmers, where a total of 50 producers were interviewed, and this sample was defined based on amount of small producers in the municipality. In addition, other resources were used, such as photographic records, audio recording, notes in field notebooks and direct and indirect observations, which also supported the research. Most respondents (46%) have been producing black pepper for over ten years, and 38% have reported growing the crop between five and ten years, 54% of producers said that the cultivation practice of the crop was adhered to. income supplementation and 32% said it was a passed on activity from father to son and the main variety cultivated by farmers (56%) is kotanadan. Thus, it was found that the main factor of cultivation of black pepper, is the complementation of income of small producers, using the variety kotanadan, because it is easily accessible in family farming of the studied region.

Highlighted Conclusion
The main factor for cultivation of black pepper var. kotanadan is the supplementation of income of familiar producers.

Keywords: Producers, Income, Varieties. (more…)

Post-harvesting of roses

Communications in Plant Sciences, vol 9, p. 70-80, 2019 (2019012)
DOI: http://dx.doi.org/10.26814/cps20190012

Post-harvest preservation of roses cv. Ipanema

Simone Lyn Van Oene, Claudia Fabrino Machado Mattiuz, Tauane Santos Brito and Renan Pan*
*Correspondence to: renanpan45@hotmail.com

Abstract: Roses are highly perishable cut flowers that demand an adequate post-harvest management seeking the maintenance of quality and reduction of post-harvest losses. Among the most used manipulations, stand out the complete cold chain, as in the producer as in the transport and storage in Garden centers, supermarkets and flower shops, besides, it can be mentioned as the most important management the use of conserving solutions, which have been proving increasingly important for the maintenance of longevity and quality. The objective of this study was to evaluate three product lines offered by the Chrysal Premium Flower Care®, which has different functions and must be used in the three stages of the cut roses chain, post-harvest, transport/storage and final consumer. During the study was considered the real farm logistic, harvest, storage, transport, sale to wholesaler “and purchase by the final consumer, in a way to approximate the producer from the result of the study and show in a practical way the efficacy of the use of conserving solutions for the maintenance of cut roses. The experiment had five treatments with two replicates each, the evaluations were carried until the end of the flower’s shelf life and consisted in: turgescence, bent neck, petals darkening, flower opening, fresh mass evaluation and water absorption. It is concluded that the operations of harvest and transport are of crucial importance in the maintenance of the longevity and quality of roses, however, it must be allied to an adequate post-harvest treatment, the investment takes the producer to opt to not use or use only one preservative. It was also concluded that the post-harvest treatment is the most indicated increasing the pot life of the stems when compared to other treatments.

Highlighted Conclusions
1. Harvest and transport operations essential for maintenance of longevity and quality of roses.
2. Operations of harvest and transport of roses must be proceeded by an adequate post-harvest treatment.

Keywords: Rosa sp., Cut flowers, Flower shelf life, Flower pot life. (more…)

Pests and diseases in pepper familiar production

Communications in Plant Sciences, vol 9, p. 66-69, 2019 (2019011)
DOI: http://dx.doi.org/10.26814/cps2019011

Main pests and diseases affecting black pepper in family production systems in Capitão Poço, Pará, Brazil

Luane Laíse Oliveira Ribeiro, Letícia do Socorro Cunha, Felipe Cunha do Rego, Francisco Lailson da Silva de Oliveira, Alysson Oliveira de Carvalho, Luã Souza de Oliveira, Marcos Vinicius Reis de Oliveira Junior, Jéssica da Silva Schmidt, Fernanda Ludmyla Barbosa de Souza, Emerson Fey, Wanderson Cunha Pereira and Francisca das Chagas Bezerra
*Correspondence to: luanelaiseifpa@hotmail.com

Abstract: One of the main problems faced by black pepper crop in the state of Pará is the phytosanitary attack that, if not controlled and / or avoided, can cause serious damages to the crop, causing productivity and financial losses for family farmers. In the city of Capitão Poço, state of Pará, pipericutura is one of the activities that contributes to complement the income of family producers, since they also work with other agricultural species. This study aimed to make a survey of the main pests and diseases most commonly found in black pepper crop by reflecting on the control methods used by family farmers in the city of Capitão Poço/PA. To collect the information, a semi-structured questionnaire was applied to 50 family farmers in the municipality, in order to identify the main phytosanitary problems faced by family producers during the cultivation of black pepper and the most used forms of control. The most common pests and diseases are aphis (70%) and mealybugs (8%) and fusarium (80%) and bacterial halo (14%) respectively, and the use of chemicals is the main form of control used. The need for the use of new techniques that minimize and / or replace chemical control is notorious, and public and private institutions may be acting in this direction, with the development of research and its dissemination, presenting other prevention and control alternatives that can be used. meet the wishes of the municipality’s producers.

Highlighted Conclusions
1. The main pests and diseases that attack the cultivation of black pepper are aphids, mealybugs, fusariosis and burning wire, using the chemical method of control.
2. It is necessary to use alternative and more sustainable techniques for pest and disease prevention and control and public and private institutions may be acting with the producers of the municipality in this aspect.

Keywords: Phytosanitary attack, Chemical control, Pipericulture. (more…)

Path analysis on oat

Communications in Plant Sciences, vol 9, p. 59-65, 2019 (2019010)
DOI: http://dx.doi.org/10.26814/cps2019010

Path analysis on traits associated with oat milling yield

Cezar Verdi, Vianei Rother, Ivan Ricardo Carvalho, Liamara Bahr Thurow, Rafael Nornberg, Victoria Freitas de Oliveira, Luciano Carlos da Maia and Antonio Costa de Oliveira
*Correspondence to: antonio.oliveira@pq.cnpq.br

Abstract: Oat is an important winter cereal used for food and feed. The industrial crop yield is an important parameter to characterize the quality of the grain and the conversion of this in processed products. Thus, this study aimed to identify the phenotypic inter-relations of cause and effect between traits associated with the industrial yield of oat. The experiment was conducted in the growing seasons of 2013 and 2014 in the experimental area of the Plant Genomics and Breeding Center, belonging to the Federal University of Pelotas. The experimental design was a randomized block, arranged in a factorial design, two (harvests) x 20 (genotypes), arranged in six replications. The oat genotypes formed different phenotypic classes for the measured traits. The industrial yield is directly associated with the test weight, grain yield and grain index. Phenotypic associations can be efficiently used in breeding programs aiming at oat indirect selection to improve industrial performance.

Highlighted Conclusions
1. Different phenotypic classes are observed for the measured traits.
2. Milling yield is associated with the hectoliter weight, grain yield and grain index.
3. The milling yield can be improved by indirect selection.

Keywords: Avena sativa L., Industrial quality, Test weight, Grain yield, Grain index. (more…)

Fleabane control after maize harvest

Communications in Plant Sciences, vol 9, p. 53-58, 2019 (2019009)
DOI: http://dx.doi.org/10.26814/cps2019009

Management of Sumatran fleabane after maize harvest in the fallow period shorter than 60 days

Antonio Mendes de Oliveira Neto*, Jamil Constantin, Rubem Silvério de Oliveira Júnior, Naiara Guerra, Eder Blainski and Hugo de Almeida Dan
*Correspondence to: am.oliveiraneto@gmail.com

Abstract: Sumatran fleabane is an important weed in Brazilian crop production systems due to glyphosate resistance and broad adaptation to no-till environments, mainly in the crop succession with soybean sowed in first-season (September to February) followed by maize in second-season (February to June). The fallow period between maize harvest and the next soybean sowing allows Sumatran fleabane to emerge and grow. On the other side, fallow is a suitable moment for Sumatran fleabane control because plants are more susceptible to herbicide in initial stages of growth. In this study, the aim was to evaluate the effectiveness on combined burndown + residual herbicide treatments to control Sumatran fleabane during fallow, after maize harvest. Two experiments were carried out in Campina da Lagoa (PR) and Floresta (PR) and treatments consisted of combinations of herbicides to provide control of emerged plants of Sumatran fleabane (glyphosate + 2,4-D, MSMA and glufosinate), applied isolated or in tank mixes with residual herbicides (metsulfuron, chlorimuron, diclosulam, imazethapyr, imazaquin, flumioxazin, metribuzin, amicarbazone and isoxaflutole) which were expected to prevent the emergence and growth of new weed fluxes. At the time of herbicides application, Sumatran fleabane plants were no taller than 12 cm. Assessments on both efficacy and residual control were performed until soybean crop sowing (45 days after treatment). Glyphosate + 2,4-D mixture was efficient for burndown of Sumatran fleabane. For fallow periods of 45 days, all glyphosate + 2,4-D mixtures with residual herbicides were efficient for Sumatran fleabane control, providing less than 10 plants m-2 and a maximum plant height of 16 cm at soybean sowing date.

Highlighted Conclusion
Glyphosate + 2,4-D + residual herbicides, MSMA + metsulfuron or chlorimuron, glufosinate + metsulfuron, chlorimuron, diclosulam, metribuzin and amicarbazone are efficient for Sumatran fleabane control since these treatments provided very low infestations and limited growth of newly emerged plants at next sowing date.

Keywords: Conyza spp., Herbicide resistance, Tank mixes, EPSPs. (more…)

Burndown and pre-emergent herbicides for soybean

Communications in Plant Sciences, vol 9, p. 46-52, 2019 (2019008)
DOI: http://dx.doi.org/10.26814/cps2019008

Weed management in soybean using burndown herbicides associated to pre-emergent herbicides

Carlos Orestes Santin, Robson Peruzzo, Leandro Galon, André Dalponte Menegat, Milena Barretta Franceschetti, Cinthia Maethê Holz, Josiel Ricardo Toni, Gismael Francisco Perin and César Tiago Forte*
*Correspondence to: cesartiagoforte@hotmail.com

Abstract: The soybean crop has been playing a very important role in the agribusiness worldwide, including in Brazil. Among the pests that cause major problems to the crop are the weeds, because they are responsible by the reduction of the productivity and of the grain quality. On the face of it, this work aimed to evaluate the application of burndown herbicides associated to pre-emerging herbicides to the management of the soybean weeds. The experiment was carried out in the field, in area with no soil cover with fallow during the winter, in the randomized block design, with four replicates. The treatments used were: diuron + sulfentrazone (490 + 245), [glyphosate + (diuron + sulfentrazone) – 1,440 + (420 + 210)], [glyphosate + (diuron + sulfentrazone) – 1,440 + (490 + 245)], glyphosate + 2,4-D (1,440 + 806), glyphosate + diclosulam (1,440 + 25.2), [glyphosate + (imazethapyr + flumioxazin) – 1,440 + (100 + 50)], glyphosate + saflufenacil (1,440 + 35), [ammonium-glufosinate + (diuron + sulfentrazone) – 400 + 490 + 245 g ha-1 de i.a], and two herbicide-free controls, weedy and weed-free. At the 7, 14, 21 and 28 days after the emergency of the crop (DAE) the variables were evaluated, herbicide phytotoxicity on soybean and the weeds control, Digitaria ciliaris and Urochloa plantaginea. In the soybean harvest, the number of pods per plant was determined, the number of grains per pods, the mass of a thousand grains (g) and the grain productivity (kg ha-1). The phytotoxicity caused by herbicides to the soybean it was not over to 8% in all the evaluations realized. The control of the weeds, D. ciliaris and U. plantaginea were over to 90%, highlighting the effect of the pre-emerging herbicides in the maintaining of the control until the evaluation of the 28 DAE. In general, all the treatments involving the herbicides did not cause changes in the components of soybean crop yield, being statistically equal the weed-free control higher than the weedy control. The soybean presented an increase of 859.48% in grain yield when Digitaria ciliaris and of the Urochloa plantaginea was controlled.

Highlighted Conclusions
1. The control of Digitaria ciliaris and Urochloa plantaginea is more efficient with the use of pre-emerging herbicides, mainly diuron + sulfentrazone and imazethapyr + flumioxazin.
2. The toxicity of herbicides to the soybean ‘NA 5909’ is low, with no visual intoxication symptoms from 28 days after emergency, and do not reduce the crop grain yield.
3. Digitaria ciliaris and Urochloa plantaginea can reduce by up to 88% the soybean grain yield if not controlled.
4. The soybean grain productivity can be increased by 859% when Digitaria ciliaris and Urochloa plantaginea are controlled.

Keywords: Glycine max, Digitaria ciliares,  Urochloa plantaginea. (more…)